# Understanding Red-Shifted Light Waves: Explained
Have you ever wondered what happens to light waves when they travel through vast distances in space? 🌌 Does light eventually lose its wave-like characteristics and become a straight line as it red-shifts further away from us? Let’s dive into the fascinating world of red-shifted light waves and explore what happens when light travels far enough.
## What is Red-Shift and How Does it Work?
### Definition and Explanation
– Red-shift is a phenomenon observed in astronomy where the light from a distant source appears more red than it should due to the stretching of the light wave.
– This stretching occurs because the universe is expanding, causing the space between galaxies to increase and the light waves to stretch out as they travel through this expanding space.
### Example
– Imagine you are standing on Earth observing a galaxy located millions of light-years away.
– As the light from that galaxy travels through space towards you, the universe continues to expand, stretching out the light wave.
– By the time the light reaches Earth, it appears more red than it should, due to the red-shift caused by the stretching of the wave.
## The Continuum of Red-Shifting
### The Electromagnetic (EM) Spectrum
– The EM spectrum consists of a range of electromagnetic waves, from gamma rays to radio waves, with visible light falling in the middle of the spectrum.
### Red-Shifting Across the EM Spectrum
– When light waves red-shift, they move towards the longer wavelength end of the EM spectrum.
– As red-shift increases, the light waves move from the visible light range (red) towards longer wavelengths like infrared, microwaves, and eventually radio waves.
### Application of Red-Shift
– Red-shift is a crucial tool for astronomers to study the distance and speed at which galaxies are moving away from us.
– By analyzing the red-shift of light from distant galaxies, scientists can determine the rate of expansion of the universe and gain insights into its evolution.
## The Limit of Red-Shifting Light Waves
### Theoretical Possibilities
– Theoretically, if light waves were to red-shift across the entire EM spectrum, they would eventually reach the limit of the spectrum, which is the radio wave region.
– At this point, the light waves would no longer exhibit wave-like behavior and would appear as straight lines in the form of radio waves.
### Current Understanding
– While this hypothetical scenario raises interesting questions about the nature of light waves, current scientific understanding suggests that light waves may not reach this extreme level of red-shifting in practical observations.
– The vast distances and time scales required for light waves to red-shift to such an extent may not be realistically achievable in our observable universe.
## Conclusion: The Wavelike Nature of Light
In conclusion, the concept of red-shifted light waves provides valuable insights into the expanding universe and the behavior of electromagnetic radiation over vast distances. While the theoretical possibility of light waves red-shifting all the way to becoming straight lines in the radio wave region is intriguing, practical observations and current understanding suggest that such extreme red-shifting may not occur in our observable universe.
So, the next time you gaze up at the stars and wonder about the mysteries of light and the universe, remember that red-shifted light waves hold the key to unlocking the secrets of our cosmic surroundings. 🌠#RedShiftedLightWaves #ASTRONOMY101 #UnlockingTheCosmos
I think you’re mistaken on quite what it means to be redshifted. It doesn’t change the amplitude of the wave (the up-and-down measurement), just the wavelength and frequency. So maybe it would eventually appear as a flat line to measuring devices that are less than infinitely sensitive, but theoretically no it could never become perfectly flat.
The decrease is exponential, the light loses a certain percentage of energy per time (assuming constant expansion of the universe). So it does, say, double the wavelength every billion years So it gets indeed larger and larger, without any boundary; but it never truly reaches infinity, becoming straight.
Maybe you can imagine the process as if the wiggling wave thing gets stretched with space, becoming lengthier; but to stretch it straight, space would have to increase infinitely.
There is no end to the EM spectrum. So it can keep being redshifted indefinitely.
There’s also a cap on how far light can go (based on the age of the universe).
The big example of this is the cosmic microwave background; this is the light that was emitted in the early stages of the universe – when the universe first stopped being opaque. This light has been redshifted (by universal expansion) as much as it is possible for any light to be redshifted, and it is currently microwave radiation (obviously), with a wavelength of around 1-2mm. Radio waves can work with wavelengths in the hundreds of kilometres. There is plenty of space for more redshifting.
Red shift is when the source of the wave is moving away from the receiver, so there is a physical change in the distance between the peaks and troughs of the waveform.
A higher frequency of light becomes more blue, and a lower frequency is more red.
The light is still considered to be coming in at the same speed, because it is a continuous wave of particles, but the swing from the “highest” to “lowest’ points take a longer time.
With a high enough speed, theoretically, the frequency of light could be so low that you receive individual photons, instead of a continuous wave, but each of those photons is still travelling at the speed of light. But that speed would be incredible, relativistic speeds.
As you look at larger and larger redshifts, the distance increases, and [asymptotes](https://en.m.wikipedia.org/wiki/Asymptote) at the distance to the edge of the observable universe. At the boundary, the redshift is infinite, which would (according to the definition 1+z=λ/λ0) imply that the observed wavelength is infinite too.
Really what this means is that light from beyond this distance is unobservable, it corresponds to light that hasn’t reached us. The interesting thing would be the extremely high redshifts as you get asymptotically close to the edge of the observable universe, though such light doesn’t exist anyway as the universe was opaque for the first 300k years.
Light isn’t changing as it gets redshifted instead the observer is moving and so the wave takes time to catch up with the eye and it is that movement which stretches out the wave.
No. Red shifting is only caused by the observer also moving, similar to the Doppler effect on sound. Otherwise, light will continue to travel infinitely at a constant rate because energy cannot be created or destroyed.
What you are describing would mean the observer would have to be traveling at the speed of light in order for it to essentially shift into net 0, but if you are traveling at the speed of light in front of a particle traveling at the speed of light then you will never be able to observe the particle in the first place. If you were going very close to the speed of light, on the other hand, the redshift would be a lot, but only ever approaching 0, never actually 0, if that makes any sense.
That is put very simply. Red shifting is actually caused by the expansion of the universe, but the idea still holds true. The rate of expansion of the universe would have to be the speed of light for the particles to no longer exist on the spectrum, but that has a few other challenging implications.
> losing its waviness and becoming a straight line?
What you’re describing is a change in amplitude, not wavelength. Redshifting changes wavelength (color). Visible light can be redshifted so far that its wavelength is unrecognizable, for example longer than the universe. But that doesn’t make it a straight line.
On the other hand, the brightness of light is its amplitude, and amplitude does reduce over distance. In theory, a light from across the universe still has amplitude, even if it’s incredibly small and hard to detect. The question you’re asking is how far does light have to travel for the height of its wave to become infinitely small and eventually zero. I’m not sure that ever actually happens.